Turn it off everytime you go in? Maybe he will get the hint. My gut said jam screws into the coin slots, but that's extra evil... Haha...
Sorry. Games earn better when they're clean, but he sees it earning as is. I called an op on a Dirty Harry and a Fastbreak here, both had dmds out. He said they're still making money so he didn't want to fix them. I guess kids dropping quarters in them at the laundromat is good enough.